Flotation apparatus



Aug. 11, 1925.

i M. KRAUT FLOTATION APPARATUS Filed April 16, 1923 2 Sheets-Sheet 1 Y IBy INVENTOR. Max ffraui;

ATTORNEY.

Aug. 11, 1925. 1,549,492

M. KRAUT' FLOTATION APPARATUS Filed April 16, 1923 2 Shoots-Shoat 2 I NV E NTOR.

BY v

ATTORNEY.

atentedl Aug. ll, 1925..

MAX. KRAUT, LOS ANGELES, CALIFORNIA.

FLOTATION APPARATUS.

Application filed April 16, 1923. Serial No. 632,369.

To aZZ whom it may concern:

Be it knownthat I, MAX KRAUT, a citizen of the United States, residingat Los Angeles, inthe county of Los Angeles and State of California,have invented new and useful Improvements in Flotation Apparatus. ofwhich the following: is a specification.

This invention relates more specifically to a single compartmentapparatus designed to be employed for the separation of mineral matterfrom the gangrue 0t ores, by the use of the well known flotationprocess.

A main object of my invention is to provide a flotation apparatus inwhich the introduction of air into the liquid pulp is accomplished byforcibly expanding the volume of the liquid pulp.

A further object of my invention is to provide a simple and eiiicientmeans for finely and evenly distributing the oils or other reagents tothe liquid mineralized pulp during operation of the apparatus.

Another object of the invention is to pro vide a flotation apparatusthat will combine highest etiiciency in operation with the lowest powerconsumption.

A still Further object oi my invention is to provide an apparatus thatwill occupy small floor space, which is simple in-construction, andeconomical in operation.

I accomplish the above objects by means of the apparatus hereindescribed and illustrated in the accompanying drawings, in which:

Fig. 1 is a central longitudinal section through the flotationapparatus.

Fig. 2 is a sectional plan view of the same taken on the line 2-2 ofFig. 1.

3 is a cross section oi the apparatus talzen on the line 33 of Fig. 1.

Fig. 4 is a sectional plan view of the, pulp deflecting ring.

Fig. 5 is a cross section of the pulp defleeting ring taken on the line5-5 of Fig. 4-.

Fig. 6 is a partial side elevation of another form of the pulp rotormember.

Fig. 7 is a partial enlarged detail cross section of the upper portionof the pulp rotating element.

The preferred form of construction, as illustrated in the drawings,comprises a substantially rectangular combined aeration and frothingchamber 10. consisting of upper side and end wall sections 11. 12, 13and 14, the lower portions 15, 16, 17 and 18 of the sections incliningtowards the center of the chamber 10, and a bottom wall 19, mounted upona suitable supporting frame work. Communicating with the bottom of thechamber is an inlet pipe 20 through which the pulp to be treated isintroduced into the apparatus, the pipe 20 passing through the inclinedportion 15 of wall section 11 and communicating with a port 22 formed inthe lower end of a vertically 6 disposed truncated conical shell orcasing 23, bolted or otherwise secured to the bottom wall 19 of theaeration and frothing chamber. The upper portion of casing 23 terminatesadjacent the upper edges of side walls 7 13 and 14 of chamber 10, and isprovided with a hollow cap or hood 24 open at its upper cud 25 toatmosphere.

Disposed in casing 23 and rigidly secured to the lower portion of avertically disposed shaft 26 is a hollow truncated cone 27. similar inconti'miration to the casing; 23. Cone 27 is provided at its lower'endwith a sleeve 28 to which the shaft 26 is rigidly secured. and at itsupper end it is provided with a 3 wall 29 havinsr a centrally disposedsleeve 30 through which the shaft 26 passes. The upper end of shaft 26passes through a hearing 31. secured to a cross beam 32 of thesupporting frame work. and on the upper end is secured a bevel drivewheel 33, which engages a frictional driving pinion 34 rigidly securedthe power drive shaft 35. power bcin o' supplied thereto through themedium of pulley 36 belted to a source of power (not shown).

The peripheral'wall of rotating: cone 27 is provided with. a pluralityof perforations 40 to permit air and atomized oil to be drawntherethrouerh to the space formed between shell 23 and rotor 27 duringthe operation of the apparatus. The upper wall 29 of the cone isprovided with a circular groove 41 having inclined side walls, and inthe bottom of this groove are a series of apertures 4-2.. preferablyfour in number, through which pass downwardly extending tubes 43, intothe interio-r of the rotor, terminating approximate- 1y at the centralportion thereof. Flotation oil or other suitable reagents are admittedto groove 41 through a distributing-pipe 44 secured to beam 32 of theframe work of the apparatus. the oil or other reagent being fed to thesupply pipe in anypreferred manner.

Secured adjacent the upper end of casing unit, but preferably they arearranged in series as shown, such an arrangement proving more efficientin the retreatment of the mineralized pulp. The upper end wall section12 which separates chamber 10 from the chamber of the adjacentapparatus, when arranged in series, is provided with a pulp overflowopening 53 controlled by a gate valve 54 of usual construction operatedby a valve lifting mechanism 55 secured to the upper edge of the wallsection. Secured on either face of wall section 12 and directly over theoverflow opening 53, are pocket or bafile constructions 56 and 57, openat their lower ends, the open end of pocket57 being connected to adownwardly extending pulp directing pipe 58 which leads to the lower endof easing shell 59 of the apparatus mounted in the adjacent flotationchamber. By means of the pocket or battle constructions 56 and. 57, thefroth carrying the metallic values will overflow the edges of the sidewalls 13 and 14 of the apparatus, while the partially treated pulppasses as heretofore noted, through the port 53 connecting the twochambers or compartments of the apparatus, for retreatment. A by passdischarge pipe 60 passes through the lower portion 17 of the wallsection 12 through the inclined section 61 of the adjacent chamber, thedischarge end terminating and communicating with the lower end of thepulp directing pipe 58 that is secured to the inclined wall of theadjacent chamber. Inclined wall 62 is provided adjacent the bottomthereof with a by pass tailing discharge pipe 63, the discharge endpassing through a vertically disposed partition wall 64, into av narrowcompartment 65 at the end of the apparatus formed by the wall orpartition 64 and wall 66. The upper edge of wall 66 constitutes a pulptailing overflow and is controlled bya gate valve 67 similar inconfiguration to the gate valve 54 mounted on the partition dividing theflotation chambers. At the bottom of wall 66 is a sand or tailingdischarge opening 68 controlled by a valve 69, the coarse sand ortailings constantly flowingthrough said opening and through a port 70formed at the lower end of the end wall 71 of the apparatus when thesame is in operation.

In order to increase and accelerate the pulp lifting power of the hollowrotating conical aeration chamber 27 a series of helical grooves 75 maybe formed in its peripheral surface, as clearly shown in Fig. 6 of thedrawings, the grooves materially assisting the upward movement of thepulp during the operation of the apparatus.

The operation of the apparatus will be understood from the followingdescription.

Power is applied through the medium of shaft 35, to the lower end ofwhich is rigidly secured the hollow truncated cone rotor 27. Pulp isthen introduced through inlet feed pipe 20 to the interior of the hollowcasing 23, the revolving rotor causing the pulp to move upwardly in ahelical path in the space between the outer and inner surfaces of therotor and casing, until it reaches the pulp discharge deflecting ring.The curved blades of the deflecting ring 50 break up the velocity of theoiled pulp and cause it to spread out radially in a thin even layer onthe surface of the pulp level in the chamber 10. It will be understoodthat while the apparatus is in operation, the chamber is alwaysmaintained in a full condition, the pulp level being kept approximatelyat the upper edge of the deflector ring.

During the upward motion of the whirling pulp, air and oil areintroduced into the interior of the hollow rotor 27 through thedownwardly extending feed pipes 43, air entering through inlet 25 formedin the upper portion of the cap or hood 24, while oil is delivered fromdistributing pipe 44 suspended from the frame of the apparatus.

The centrifugal force geherated by the re-- volving rotor spreads theoil or other reagents into a thin layer. There is a tendency to create apartial vacuum in the space between the rotor and its enclosing casingor shell. and consequently also in the interior of the hollow rotorwhich is in communication with the space between the casing and rotorthrough the perforations 40. It will thus be seen that air will be drawnin through the pipes 43, absorbing in its travel the oil or other liquidreagent, which step is essentially an atomizing process, the atomizedair and oil being drawn into the whirling mass of pulp where it becomesthoroughly mixed. The aerated and oiled pulp when discharged through thedeflecting ring 50, spreads itself in a thin layer on the surface of theliquid pulp forming bubbles which accummulate in a mass of frothcarrying the metallic sulphides and overflowing the edges of the sidewalls 13 and 14 of the apparatus.

The circulation of the liquid pulp through the apparatus is accomplishedby means of the cone shaped rotor 27 for the following reasons. It willbe observed that the diameter of the upper end of the rotor 27 isgreater than at its lowermost end, and as a reaaeoa consequence, thevelocity imparted to the circulating pulp will be greater at the upperend than at its lower end. Inasmuch as the internal pressure of a movingliquid decreases as its velocity increases, therefore the pressure atthe lower end will be greater than at the upper end, causing the liquidpulp to rise in the space formed between the rotor and its casingin ahelical path until it discharges through the deflecting ring into thepulp and frothing chamber of the apparatus.

When the pulp level in the chamber of the apparatus reaches apredetermined height it overflows into the adjacent tank of the series,the overflow being directly connected to the intake openings of therotor of the adjacent section, as heretofore described. By thisconstruction the pulp level of each chamber in the series may beindependently regulated, thus allowing greater flexibility in theoperation of the apparatus.

From the above description it will be observed that the apparatus willconsume very little power for its operation as the power required variesdirectly as the square of the diameter, and is directly proportional .tothe number of revolutionsof the rotor. As

the diameter of the rotor is comparatively small, it follows that itwill only be necessary to employ a correspondingly low proportion ofpower, a rapid circulation and a thorough aeration being efl'ected witha minimum expenditure of energy. lBy forming helical rooves in thehollow rotating cone, the lifting power of the cone will be ma teriallyindreased; however, in practice the smooth surfaced cope has producedexcellent results.

What I claim is 1. A flotation apparatus, comprising a chamber open atits upper end, a rotary pulp aerating element disposed therein, a casingmounted in said chamber and surroimding said element and spacedtherefrom to form a passageway circular in cross sec-.

tion and uniformly increasing in diameter from its inlet toward itsdischarge end, means to deliver a liquid pulp to the passageway formedbetween said aerating element and casing at the lower end thereof, andpower means to drive said aerating element.

2. A flotation apparatus comprising a chamber, a pair of concentricallydisposed conical members vertically positioned there in with theiradjacent wall surfaces lying in spaced relation, forming a pulp passage,apulp inlet leading to the lower end of the pulp passage, and means forrotating one of said conical members.

8. A flotation apparatus comprising a single aerating and frothingchamber, a ver tically disposed hollow-truncated cone for circulatingthe pulp, an enclosing conical shell surrounding said cone and with itsinner wall parallel spaced from the periphery thereof, said cone walland shell wall affording a pulp passageway between the cone and shell, apulp inlet leading to the lower end of the passageway between the coneand the shell, and means to rotate the cone.

4. A flotation apparatus comprising a chamber, a ,pair of concentricallydisposed conical members vertically positioned therein with theiradjacent wall surfaces lying in spaced relation, forming a pulp passage,a pulp inlet leading to the lower end of the pulp passage, and means forrotating the inner one of said conical members.

5. In a flotation apparatus, the combination of a single compartmentpulp aerating and frothing chamber having a pulp inlet leading thereto,a vertically disposed perforated hollow truncated cone aerating elementmounted in said chamber and means for rotating the same, a hollowconical casing of substantially the same form as said aerating elementenclosing said aerating element and spaced apart therefrom to form apulp passageway, the pulp inlet leading to the passageway at the bottomof said casing, whereby the liquid pulp will be caused to move upwardlyin said passageway on a rotation of said aerating element, a pulpdischarge and deflecting means mounted-in the upper portion oi: saidenclosing casing, and neansfor introducing air and a reagent into theinterior of said aerating element.

6. A flotation apparatus, comprising a single aerating and frothingchamber, a vertically disposed hollow perforated truncated cone forcirculating and aerating the pulp, a conical enclosing shell surroundingsaid cone and spaced apart therefrom and having a pulp inlet at thebottom thereof leading to the space formed between said cone andenclosing shell, means to admit air and oil to the interior of saidhollow cone, a pulp discharge opening tormed at the upper end or saidenclosing shell, and means to rotate said cone. 7

7. In a flotation apparatus, the comblnallti tion of a singlecompartment pulp aerating nae same, a hollow conical casing enclosingthe cone and spaced apart therefrom to form a pulp passageway, the pulpinlet leading to the passageway at the bottom or said casing, wherebythe liquid pulp will be caused to move upwardly in said passageway on arotation of said cone, a pulp discharge and deflecting means mounted inthe upperpor- 1 tion of said casing, oil and air distributing meansmounted on said hollow cone and communicating with its interior, andmeans to supply a liquid reagent to the interior of said cone.

8. A flotation apparatus comprising a chamber, a pair of concentricallydisposed conical members vertically positioned there in with theiradjacent wall surfaces lying in spaced relation forming a pulp passage,one of said adjacent surfaces being provided with a'pulp elevatingprojection arranged at an upward inclination, a pulp inlet lead ing tothe lower end of the pulp passageway, and means for rotating one of saidconical members.

In witness that I claim the foregoing I have hereunto subscribed my namethis 30th day of March, 1923.

MAX mam".

